Hemianthus Micranthemoides (Hemianthus micranthemoides) Care Guide
A delicate small-leaved stem plant that can be used as either a midground bush or a carpeting plant when kept trimmed low.
Compiled by Aquairi from published sources · Published · Updated
Overview
Hemianthus micranthemoides is an aquatic plant in the family Linderniaceae. A delicate small-leaved stem plant that can be used as either a midground bush or a carpeting plant when kept trimmed low. Its tiny bright-green leaves create a fine texture that contrasts beautifully with broader-leaved species.
Taxonomy
- Family: Linderniaceae
- Genus: Hemianthus
- Scientific name: Hemianthus micranthemoides
- Other names: Baby Tears, Pearl Grass
Habitat
Originally described from freshwater estuaries of the U.S. mid-Atlantic states (Virginia to New York), where the wild taxon Micranthemum micranthemoides is listed as possibly extinct. Plants traded in the aquarium hobby under this name are most often the closely related Micranthemum glomeratum.
Growth requirements
- Light: medium (≈50-80 PAR at substrate)
- CO2: pressurised CO2 recommended
- Temperature: 20-28 °C
- pH: 6-7.5
- GH: 3-10 °dGH
- Substrate: nutrient-rich aquasoil or fertilised gravel
- Nutrient demand: medium
- Growth rate: medium
- Difficulty: intermediate
Placement
- Recommended placement: midground
- Maximum height: 15 cm
- Trim every: 10 days
Propagation
In cultivation the plant is propagated by stem cuttings (replant the upper portion after trimming).
Propagating Hemianthus micranthemoides (Pearlweed)
Overview
Pearlweed is a fine-textured small-leaved stem plant whose bright-green foliage contrasts well with broader-leaved species. The historic species Hemianthus micranthemoides, native to wet areas from Virginia to New York, is listed as possibly extinct and was likely never cultivated; plants sold under this name in the hobby are a related Micranthemum from Florida. In the aquarium it can be a background shrub or a foreground plant depending on how short it is cut.
Propagation Method
Pearlweed propagates from cuttings. You snip off the tops and replant them in the substrate, where they root readily. Because it grows fast, a single healthy clump quickly yields plenty of cuttings, making it one of the easier stem plants to multiply.
Step-by-Step
- Select vigorous tops and cut pieces about two to three inches long with clean scissors.
- Replant each cutting into the substrate, spacing them so the new stems have light and room to bush out.
- For a carpet, plant pieces close and let the stems run sideways; for a bush, plant upright and trim side growth.
- Leave the parent clump to regrow from the cut points and supply further cuttings.
Conditions for Healthy Growth
Pearlweed is a fast-growing stem plant that benefits from CO2 injection and strong light, and it grows noticeably better in medium light than in low light. Given good light and CO2 it establishes quickly and spreads, which is what makes it forgiving compared with more demanding fine-leaved species.
Trimming & Maintenance
Trim regularly, roughly every ten days, to keep the stand dense and at the height you want. Each trimming is itself a batch of cuttings, so maintenance feeds propagation. The plant is often raised emersed before sale, then converts to its submersed form once settled in the tank.
Common Challenges
Pearlweed tends to grow horizontally and carpet rather than stand tall, with stems running sideways and rooting down. If you want the upright bushy look you must persist in trimming the side shoots and roots to force vertical growth. In low light it grows poorly, so raise the light before blaming other factors.